Adjusting the Z- axis on RepRap type printers

RepRap type printers use two linked steppers to move the extruder up and down through a pair of threaded rods. In order to calibrate the Z-Axis so that Z = 0 is approximately 0.2 mm from the print plate, it is necessary to turn each threaded rod. Turning the rod clockwise will lower the extruder, and anti-clockwise will raise it away from the plate.

To make it easier to turn the rods, obtain two hexagonal nuts and two wingnuts to suit the thread of the rods. Fit one hexagonal nut to the top of each rod, then fit a wingnut above it so that the tip of the rod just starts to come out of the wingnut. Then unwind the hexagonal nut until it contacts the bottom of the wingnut and tighten the nut and wingnut against each other.

With the wingnut locked in place by the hexagonal nut, you will be able to turn the rods by grasping the wings. The wings also give you a marker to count the number of turns you make.

Remember to turn off the power to your stepper motors when making any adjustments via the rods. If there is power to the steppers, they will he generating holding torque qhich you have to overcome to move the rods. With the power off, the rods move freely and you can make more accurate adjustments.

Old Man Emu